Automatic furnace-regulator.



M. J. & H. B. FARQUHAR. AUTOMATIC FURNACE REGULATOR.

APPLICATION rum) JAN. 30,1905.

3 7 3 V Patented June 1,1909.

I Specification otLetteraPatent.

STATES 1?ATEN T OFFICE. MILTON J. FAR I-JH-ar. AND; HENRY B. FARQUHAR,or WILMINGTON,

DIRECT 'AND MIESNE ASSIGNMENTS, TO nun .MINGTQN, 01110,; ooRPoaAmo in10.

' 1 j awom'mc runnacnmnem'ron.

FARQUHQIFL FURNACECOMPANY, OF WIL- Patented June 1, 1909.

OHIO, ASSIGNORS, BY

Oflxinal implication flledilarelr i b, 1902,8erla1 No; 98 ,:445. D1v1dedand thls appltcaflon flied {mumv.80, 1905.

v v s m aagaasa,

To all whm'tmiytmm:

residing at .Wilcounty of of Ohio, have inventedcertain new and usefulImprovements in Automatic Furnace- I applied to a furnace aforesaidapplication Re ulators' foll heat regulatin ciples' explained, or

and we do hereby declare the owing to be, a full, clear, and exactdescript-ion of the invention, such as will enable others skilled in theart to which it appertains to make and use the same. v This invention(for which the resent-application is filed as a division 0 our pendmgapplication Serial No 98445, filed March Hot air furnace relates tofurnaces, in

'clusive also of stoves or similar heating a paratus,

and more particularly to automatic mechanism for rendering the furnaceor re-box self-regulating.

The invention embraces a novel reliable heat-governor operated by theexpansion and contraction of the fire-box; the object of which is toeffectively control automatically the temperature of the fire-box andregulate the combustion of fuel to best advantage.

7 In the accompanying drawings, which form a part of this specification,we have represented the automatic heat-regulating mechanism embodyingour present invention such as shown in our Serial 'No. 98445,

wherein the general arrangement of the fire-v fines etc., is horizontal,the products of combustion passing out through an indirect draft flue.-While certain claims are made herein to the general combination ofsuchafujrnace and automatic governing mechanism .operating on the prinperforming substantially the same functions, it will'be understoodnevertheless that the present invention box, airand smoke is notessentially limited to the construction and embodiment shown, and thatthe heatregulator or mechanism 4 constituting the Clinton and Stateings, and then more mechanism tothe 15, 1902, for an invention entitled-Ii 3 principal: feature of this case is susceptible Be, it known thatwe, M1L'roN- 'J.;Fm5 QUHAR and HENRY B. Fanqunamboth citi zens'of theUnited States, mington, in the of other applications and wide utility,while are also susceptible to modifications. With these remarks in View,the invention will be its 'detai-lsof construction and arrangement fullydescribed with reference to the draw? articularly pointed out anddefincdin the c aims at the end of the description.

Fi gitu inal. vertical section of. the furnace. Fig. 2 is a fragmentaryside elevation showing the relation of draft and check-doors. Fig. 3 isa perspective View, showing a portion of the air-box broken away anddisclosing the interior fire-box. Fig. 4 is a detail view of theadjuster for. the regulating mechanism. Y

Inasmuch as no specific claim is made herein to the improvedconstruction of the fire-box per 86 (since the same isfully describedand claimed in our aforesaid application Serial No. 98445), a briefexplanation of its construction, and operation will be sufficient.

The numeral 1 denotes the outer casing of the air-box; and 2 is thefire-box,3 its backplate and 4 its front plate. The fire-box'is inclosedwithin the air-box, except its front plate 4, which is outside the frontwall-of the air-box and has dampers, of which 12 is the fire-door, 13the ash-door, and 14 the check-door or valve of the smoke-box 10, whichis shown located at the base of the furnace front. The fire-box is shownof horizontal tubular form, so that the direction of its expansion tionis longitudinal of the furnace.

the automatic regulating all the necessary doors or.

and contrac-' me 1 of the drawings is a central 1011-.

" Within the fire-box, 6 denotes the fire-pit or i fuel,-space;15 theash-pan below the ate; 7 aflue or passage behind the rear. bri ge-wall9, or between it and the back-plate 3 of the furnace; and 8 aflue orpassage in the bottom of the fire-box formed-along under the ash-pan tothe smokefrom said passage 7 The heat-governor or re box 10. Theproducts of combustion pass over the rear bridge-wall down the passage 7and forward through the flue or passage 8 to the front smoke-box, whichhas an outlet opening to the chimney or smoke-pipe 11.

Air is of course supplied to the fuel from the ash-door, passing upthrough the grate; and in this our improved type of furnace, preferablyan air-blast is also admitted. from the rear of the ash-pan up through apassage in the bridge-wall 9 to the fire-space above the fuel, where itmeets the gases at a heat sufficint to ignite the mixture.

lating mechanism operates upon the ashoor 13- to control the airadmitted to the fuel, and upon the check-door 14 in the smoke-flue orsmokebox 10*to check the draft when necessary. It utilizes a weight, as15, to open the ash-door, and the force of expansion of the fire-boxwhen heated against an inclosing framework not heated to close theash-door and open the check-door. Said frame-work, as shown, consists ofa rear cross-piece 16, having pins or projections 26 that bear againstthe rear wall 3 of the fire-box to receive the thrust therefrom when thefire-box expands with heat; and a front cross-piece '17 and oppositeconnecting rods 21 and 22; the

rod 21 connecting one end of the rear crosspiece 16 with an adjustinglever 20 attached to the front cross-piece 17, which has a graduated arc18 and a locking rack 19 for holding said adjusting-lever in place; andthe other rod 22 connecting. the opposite end of the rear cross-piece 16with a pendent lever 23 shown fulprumed at on the front-crosspiece 17 soas to draw said lever, inward when the expansion of the fire-box actsagainst the inclosing frame-work 16, 17, 21, 22, etc., with sufficientforce to overcome the I Weight 15, which tends to hold said lever 23outward. The lever 23 is rocked on the edge or fulcrum 2% formed on thebar or front cross-piece 17. Pivotally suspended as at 25 from its lowerend is a bent lever 28', the elbow 27 of whifli is a sliding fulcrum.From the lower part 31 of this lever extends a for ward arm 32 carryingthe aforesaid weight 15. When the furnace is at low temperature, theweight 15-holds the upper part 30 of bent lever 28 outward, and therebyholds outward the lever 23 also. In this position, a lug 33 on the upperpart 30 is out of contact with the lug 29 on the ash-door. Now, when therising temperature and consequent expansion of the fire-box pulls theconnecting-rod 22 rearward, it pulls the lever 23 inward, likewisemoving the upper part 30 of the bent lever 28 toward the stove, allowingits fulcrum 27 to slide downward. Said upper part 30 now carries with itthe ash-door 13, by virtue of the engagement between the parts 33 and29. The same movement, if continned after reaching the position forholding the ash-door closed, changes the fulcrum of the lever 28 to 29,and raises the lower arm 32 and with it the check-door 14, a la 34 fromwhich overhangs the said arm. T ese movements tend to close the ash-doorand open the check-draft door.- The purpose in opening the latter is tosupply the necessary draft to the chimney from the outside, instead offrom the fire-box; thus relieving draft from the fuel. This mechanismwill automatically maintain just the necessary opening of the ash-doorto providethe requisite draft for kee ing a practically constanttemperature. ture will be compensated for by restriction of the ash-dooropening, and any sudden or,v

great increase by openin of the check-door. Any decrease from thedesired temperature will be compensated for by the outward movement ofthe lever 23, which draws upward the lever 28, whose lower inclined part31 engages the lug 29 and opens the ash-door. The inclosing frame-work16, 17, 21, 22, etc., can-be extended or shortened by the adjustinglever 20, so as to cause the expansion of the fire-box to act on theframe at different temperatures; so that the furnace may be arranged tomaintain the desired tempera ture. The said frame-work may surround thefire-box as herein-described, or may occupy one side only, beingsuitably connected with the front and rear plates of the fire-box.

The broad principle of the heat-regulator is the transmission of motiondue to expan sion of the fire-box through a non-expanding member to asuitable lever-mechanism for controlling the position of the draft orcheck; doors. To secure sufiicient action, it is important that thenon-expanding member be kept as cool as possible; and it is thereforeprotected by a shield, being in the present instance placed outside thecasing of the airbox where it is shielded from the rays of heat frontthe fire-box and where it is kept cool by exposure to the surroundingair.

o claim as our invention and desire to secure by Letters Patent of theUnited States:

1. In a furnace, the combination with an expansible fire box andsurrounding air-box or casing for the medium to be heated, of a foursided frame-work not affected by heat inclosing the air-box and arrangedto re ceive the thrust from expansion of the firebox, and regulatingmechanism for the draft opening or openings operated by said frameworkwhen moved by expansion of the furnace.

2. In a furnace, the combination with a heater having a draft-door, of athermostatic governing mechanism comprising a pendent lever, asecondintermediately-fuL crumed lever pendent from said first mentending tohold the same position to maintain said door 0 en, and heat-governed.means connected wit said first mentioned lever for moving the same underrise of temperature in a direction which moves the second lever in amanner to close said door.

3. In a furnace, the combination with an expansible fire-box providedwith a draftdoor and check-door, of a vertically-dis posed lever (28)intermediately fulcrumed and connected with said draft-door and providedwith a' weight for holding said lever in a position to'maintain saiddraft- -door open, and mechanism connected withsaid fire-box andactuated by expansion thereof and connected with said lever for movingthe same in a direction to close said door,'and means .whereby saidcheck-door is controlled by said lever.

The combination of a horizontallydisposed expansible fire -box, and asurrounding casing for medium .to be heated, of a non-expandingframe-work surrounding said casing and com rising front and rearcross-pieces at the front and rear of the furnace respectively, atie-rod connecting-said cross-pieces at one 'sideofthe furnace, adamperscontrolling lever fulcrumed on one of said cross-pieces, and atie-rod connecting the opposite cross-piece and said lever and arrangedat the other side of'the furi iace, and means extending from one end ingsaid rame-work receives aainst one of said cross-pieces, whereby thethrust of ex pansion of the fire-box.

The combination with the expansible lire-box, of the non-expandingframe-work comprising front and. rear cross-pieces, a damper operatinglever fulcrumed on one cross-piece, a rod connecting saidlever with theopposite cross-piece, an adjustin lever connected to one cross-piece and'aving means for locking; it in place, and another rod connecting saidlever and the other cross-piece. v 6. The combination with the ash-doorand check-door, of a endent lever, a bent lever pivotally-suspen edtherefrom whose elbow constitutes a slidin fulcrum, and having a lowerarm underlying a In on the check door, temperature control ed means formoving said pendent lever inward and out-- ward, inward movement thereofcausing inward movement ofthe upper part of said bent. lever, and meanswhereby on such inward movement of said upper part it en gages and"moves inward the ash-door, while the continued movement after the dooris closed causes the said lower arm to lift the check-door.

7. A furnace having, n combmation, a

of the fire-box through said casing and bearsite cross-piece at one sideof the horizontallydisposed tubular fire-box rovided with a front firedoor and ash oor thereunder, said firebox having an internal grate andash pan so arranged as to provide in the rear and bottom of the fire-boxan indirect draft and smoke passa c, said passage having its finaloutletat te base of the front of said fire-box, a smoke-pipe or chimney inc'oimnunicataon with said final out-let, a check-door under the ash-doorfor controlling admission of air into said smoke-pipe, and mechanismmounted on the furnace operated by expansion and contraction of. thefirebox and including a front pendent lever connected withthe ashdoor andcheck-door for automatically controlling the same.

8. In a furnace, the combination with an expansible, fire-box andsurrounding air-box or casing for the medium to be heated, of aframe-work not affected by heat inclosing the casing, means for impartinthe thrust of expansion of the fire-box to sai frame-work, 'a draftdamper, and a lever operated .by said frame-work'for controlling saiddamper.

9. In a furnace, the combination with a horizontally expansible fire-boxand surrounding air-box or casing 'for the medium to be heated, of anon-expanding frame-work surrounding the casing, thrust pins interposedbetween the rear cross-piece thereof and theback of the fire-box, andadamperiz mtrolling mechanism actuated by said ame.

fire-box, of' the non-expanding frame-work surrounding the furnace andcomprising 'ating lever fulcrumed on. one cross-piece, atie-rodconnecting said lever and the oppo furnace, and an adjustable tie-rodconnecting said cross-pieces at the opposite side of' the furnace, thesaid frame-work being ada ted to {)eceive the thrust-of expansion of t efire- 11. In a furnace, the combination with the hinged ash-door'havinga lug thereon, of a pendent bent lever whose elbow constitutes a slidingfulcrum, the upper part of said lever having a lug overlying the lug onthe ash-door, heat controlled means connected with said lever fordrawing its upper art inward as the temperature rises, an a lever.

hinged ash-door having a lug'thereon, ofa pendent bent lever whose elbowconstitutes a sliding fulcrum, the upper part of said lever having alugoverlying the lug on the ash door, heat-controlled means connectedwith said lever for drawing its upper part inward as the temperaturerises, a h nged check-door 10. The combination with the expansible frontand rear cross-pieces, a damper-'operweight acting upon the lower partof said 12. In a furnace, the combination with the having a lugoverlying the lower part of heater to rock both of said levers and closesaid lever, and a weight acting upon the said door when the heaterexpands.

lower part of said lever. In testimony whereof we aflix our signa- 13.The combination with a'longitudinally tures, in presence of twowitnesses.

-5 expansible heater, provided with a draft MILTON J FARQUHAR door of apendent level" asecond lever, provided with a weighted end, pendentthere- HENRY FARQUHAR' from and adapted to engage said draft-doorWitnesses: and normally hold it open, and means con- C. W. SWAINE,

- 10 meeting said first mentioned lever and said E. R. K. HAYES.

